1. Technical Field
The present invention relates to electronic panel displays and more particularly, to such displays with touch sensors.
2. Discussion of the Related Art
Prior to setting forth the background of the invention, it may be helpful to set forth definitions of certain terms that will be used hereinafter.
The term “physical touch event” as used herein refers to an actual physical contact initiated by a user, between a user or an object held by the user, and a display panel. The outcome effect of such an impact may result with any of the following measurable metrics: force/pressure change, bending, deflection, shockwave, acoustic pulse/wave, dispersive signal, and the like.
The term “physical touch sensors” as used herein refers to any type of sensors that are configured to measure any of the aforementioned measurable metrics associated with the various types of the outcome effect of the physical touch event.
The use of touch screens on board airborne platforms has recently become very popular with the introduction of flat panel displays. One form of touch screens is based on optical imaging technology (hereinafter: optical touch screens). Optical touch screens usually include one or more set of optical sensors positions along the circumference of the display. In combination with a processor, the optical sensors determine the spatial position of the hand or finger the user or any object held by the user. By determining an optical touch plane, which is usually parallel to the actual screen, any crossing of that optical touch plane is considered as a touch event. One drawback of the optical touch screen is that the optical touch plane is displaced, from the actual screen and so the optical touch screen detects a touch event before a physical touch event has occurred.
A range of technologies are used today in order to implement touch screen that are based on detecting a physical touch event. Piezoelectric sensors for example are used as pressure or acceleration sensors. Using a computer processor and algorithms, the location of the hand or an object held by it, may be determined Other physical touch sensors technologies such as capacitive and resistive sensors are also widely used. The capacitive and resistive sensors tend to be placed on transparent layer on the side of display panel facing the user and are known to cause a certain degradation of the quality of the image displayed by the panel display. Other types of sensors configured to measure the aforementioned metrics of the physical touch event are also known.
Displays intended for use in harsh environments such as airborne platforms, military vehicles, and the like are affected by vibrations and shocks during normal operation. Consequently, any touch screen that is based on recognizing the actual contact or impact of a physical object with the display may be interfered by the aforementioned vibrations. It would be advantageous to provide a method or a device for validating a physical touch event in optical touch screen, in which a user has intentionally caused a physical touch event.